Apoptosis is beginning to yield its secrets to a combined attack of cellular and molecular biology and biochemistry. Models have been developed in invertebrates that have pointed the way to corresponding genes in mammals. Apoptosis can be signaled via surface molecules like CD95, and abnormalities of this process in patients have now been identified. The signaling pathways are still obscure but strong new evidence implicates membrane-derived lipids and calpain-like and ICE- like cysteine proteases. Regulatory mechanisms being unraveled include the interactions of pro- and anti-apoptotic members of the Bcl-2 family; viral genes that mimic these molecules have provided important clues to their function. Although much is known about individual parts of the apoptotic pathway, we are a long way from integrating the information. Whether there is a "final common pathway" in apoptosis remains the key question. This conference will bring together a multidisciplinary group of workers from a broad range of backgrounds in an attempt to build a synthesis of what is known, and focus on the questions that still need to be answered. Unlike other recent conferences, we are not limiting our discussion to a single area (for example the immune system or cancer) but are trying to cover the important concepts at the most fundamental level. It is these basic properties of the apoptotic process that transcend any single discipline. There are still considerable areas of controversy in apoptosis research, and we have intentionally invited the key proponents of differing views; for example, we will get a chance to compare the transduction theories of killer T-cell mediated apoptosis (CD95) to the injection theory (granzymes), and hear three apparently rival models of protease-mediated signaling. This conference is unique in covering all aspects of apoptosis from signaling, through biochemical mediators and genes, to cytoskeletal alterations, cell shrinking, membrane changes, phagocytic recognition, and ultimate fate; from C. elegans through Drosophila to humans; from embryogenesis to senescence. About half the invited speakers also spoke at the first Keystone apoptosis conference, and half are new; half are established apoptosis investigators, and half are less familiar even to an apoptosis audience. Our sole criterion was superb recent work and the ability to convey it to an audience of mixed background. We have centered our efforts on providing an unmatchable educational experience for graduate students and postdoctoral fellows.